Thermostat.



PATENTED MAR. l0, 1908,

F. P. BUTMAN. THERMOSTAT.

` APPLIOATION FILED mmvfleoa.

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FRED P. BUTMAN, OF HOLBROOK, MASSACHUSETTS.

THERMOSTAT.

Specification of Letters Patent..

Application filed March 27, 1903.

Patented Marcil 10, 190s.

serial No. 149,904..

To all 'whom it may concern:

Be it known that I, FRED P. BUTMAN, a citizen of the United States, and resident of Holbrook, in the county of Norfolk and State of Massachusetts, have invented new and useful Im rovements in Thermostats, of which the fo owing is a specification.

My invention relates to therniostatic devices ofthe kind which are applied to journal bearin s and o erate to give an alarm caring becomes unduly heated,

' the object of my invention being to provide or shel a device of the character referred to which shall be simpler and less expensive of construction, and more certain in its operation, than those heretofore employed.

In the accompanying drawings z-Figure l is an elevation of a therniostatic device embodying my invention, as ap lied to ajournal bearing; Fig. 2 is a centra vertical section through the device itself showing the parts in their normal position; and Fig. y3 is a similar section showing .the parts of the device after it has operated to give an alarm.

The working parts of my device are inclosed in and protected by a casing of suitable construction adapted to be set into a hole formed in a journal bearing, my casing being shown in the drawings as composed of a metallic, cup-shaped portion 2 and a detachable cap 3 forming a closed chamber. The cup 2 is provided with an annular ledge 4 and contains a movable member composed of a metallic disk 5 provided with a pin 6 extending downward into the hollow lower end of the cup 2. Between the disk 5 and the ledge 4 is inter-posed a spring 7 which, when the parts are in the osition shown in Fig. 2, tends to force said isk and its pin 6 upward. This spring has the form of a tapering spiral with its larger portion or base resting u on the ledge 4. A short distance above t e disk 5 are located two con ducting terminals 8, 8 which are insulated from each other by being passed through a disk 9 of vulcanized fiber or similar material,

which is screwed into the upper end of the cup 2. These terminals 8, 8 are respectively connected to insulated conducting wires 10, 10 whichlead out through the top yof the cap 3, which is screwed onto the top of the part 2, as shown. The wires 10, 10- are included in an alarm-circuit which is not herein shown, the construction and arrangement of such circuits being `well understood.

In the normal condition of the device, the

lower end of the pin 6 is secured to the bottom of the cup 2 by fusible solder of such composition that it will melt at a predetermined temperature, and in case the journal bearing to which the device is applied is heated .above the given temperature, by friction or otherwise, the heat is communicated through the metallic cup 2 to the fusible solder, which thereu on melts and releases the pin 6 and the isk 5. The spring 7 thereupon forces the disk 5 into contact with the terminals 8, 8 and thus completes the circuit through the alarm device.

In order to revent the detachment of the device from tie journal bearing to which it is a plied, the lower portion of the cup 2 is pre erably. screwthreaded externally and screwed into a suitable hole provided for it in the journal bearing, and it will be evident that after the disk.9 has been screwed into place and the wines 10, 10 have been connected into the alarm circuit, it will be practically impossible to detach the device from the journal bearing because it cannot be unscrewed therefrom without twisting the wires.

The peculiar shape given to the spring 7, and its employment in connection with the ledge 4, are features of my invention, as this arrangement prevents all possibility of the action of the spring being interfered with by its catching on the pin 6 or by having its coils clogged by fragments of melted solder, as has been found to occur in the operation of certain prior devices for the same purpose. When my spring 7 is compressed, as shown inFig. 2, its coils nest one within another, presentinga substantially flat and unbroken surface without spaces between the coils, and at a considerable distance from the lower end `of the in 6 and the solder, and when the solder Fuses the. coils can separatewithout anylf` possibility of being interfered with.

he upper portion of the part 2 is made large venough to receive ones finger, so that the device may beset by removing the cap 3, unscrewing the disk 9, using the outer ends of the terminals 8, 8 as handles, pressing the disk 5 downward by inserting a finger into 'the top of the enlarged top portion of the cup 2, and holding the device with its bottom surfacein contact with some part heated to a sufficient temperature to'melt the solder. 'As soon as the solder is melted, the device is removed from the heated part and the disk5 is still held down until the solder has cooled and set, whereupon the disk 9 is screwed into place, the cap 3 is applied, and the termina wires are connected into the alarm circuit. Thus the Vdevice may be re-set after operation, as many times as may be necessary. The internal diameter of the extreme lower end of the cup 2, where the solder is located, is referably made just suflicient to receive theower end of the pin 6, as shown, so that only a very small amount of solder is required and the pin 6 is necessarily brought into contact with the solder when the device is re-set.

It will be observed that the disk 9 'forms a tightly fitting cover which eflectually seals the cup 2 and prevents the introduction of dirt or moisture into the saine through the opening in the top of the cap 3. rlhe wires 10, 10 are led from the terminals 8, 8 Iout through the cap 3 .and are preferably provided for a short distance with a wrapping or cover 11, in order to protect their insulation from rubbing contact with the cap 3.

I claim as my invention:

l. In a thermostat for journal bearings the combination of a cup 2 having a closed bottom formin a solder-retainin receptacle and provided a ove the same wit aledge 4, a disk 5 having a pin 6 n`rmall secured in the bottom of said cup by fusi le solder, a tapering spiral spring havin its base resting upon said ledge and its sma er end bearing against said disk, the coils of said spring being normally nested one within another. and means for completing an electric circuit through said disk upon the melting of the fusible solder.

2. In a thermostat for journal bearings, the combination of a cup having av closed bottom forming a solder-retaining receptacle and also having an open top adapted to permit the resetting o f the device, an insulating disk 9 detachably screwed into the open top of said cup, Contact terminals passing through lsaid disk and servin as a means'for turning the same, a disk 5 coated beneath said insulatin disk and having a downwardly-exten ing pinnormally secured to the bottom of the cup by fusible solder, and a spring tending to force said disk 5 upward.

3. In a thermostat for journal bearings, the combination of a cup 2 having a closed bottom of restricted diameter as compared With the upper portion of the cup and forming a solder-retainin receptacle, an `insulating disk 9 detachab y secured in the open top of the cup and provided with contact terminals passing through the same and adapted to be included in an alarm circuit, a disk 5 contained in said cup beneath the disk 9 and provided with a downwardl extending pin having its lower end normallry secured within the restricted bottom of thereln, and a spring tending to force said disk 5 upward, the sides of the cup above its restricted bottom being tapered to act as' guiding surfaces for said pin 1n resetting the evice.

4. In a thermostat for journal bearings, the combination of an externally screwthreaded cup 2 having a ledge Litand `closed at its top by a detachable insulatin disk 9, a disk 5 movable in said cup above t e ledge 4 and provided with a pin normally secured to the bottom of the cup by fusible solder, a tapering spiral vsprin between said ledge and movable disk, lns ated conducting ins 8 passing through 'the disk 9, wires lea ing from sald pins respectively, and a cap 3 detachably secured to the cup 2, substantially as described Y l 5."In-a thermostat for journal bearings, the combination of a cup 2, an insulatin disk 9 detachably secured to the top of said cup andformin a tight cover for the saine, a

cap 3 detachab y secured to the cup v2 and rovided with a central perforation, the interior of said cap forming an inclosed chamber, contact terminals passing through the disk 9 and extending upward therefrom into the interior` of said cap, circuit wires connected to said contact terminals respec tively within said cap and passing loosely through the perforation therein, and means contained within the cup 2 for establishing a circuit through the contact terminals at a predetermined temperature.

6. In a thermostat for journal bearings, the combination of a cup. 2 having a closed the i cup by means of fusible solder contained bottom forming a solder-retaining receptacle of restricted diameter as' compared with the upper portion of the cup, an insulatingv disk 9 detachably secured in the open top of said cup and provided with contact terminals assmg through the same and adapted to be included in an alarm circuit, and a spring-actuated disk 5 contained in said cup beneath the. disk 9 and provided with a downwardly extending in 6 havin its lower endl normally secured)\vithin sai restricted receptacle by fusiblesolder contained therein.

In testimony whereof, I have hereunto subscribed my name this twenty-fourth day of March, 1903.I

FRED P. BUTMAN. Witnesses:

E. D. CHAnwrox, JOSEPH T. BRENNAN. 

